Patent GB-411460-A (GB)
Title: Improvements in or relating to rubberised and vulcanised fabrics and like products
IPC: D06M15/693
Filed: 1932-12-06
Abstract: A process for the production of vulcanized articles of textile material consisting wholly of threads, yarns or the like which have been impregnated with and surrounded by rubber by immersion in an aqueous dispersion of rubber while the said dispersion is subjected to fluid pressure, comprises forming the articles by weaving, braiding or like operation, and treating with a rubber dispersion so that the stress.strain characteristics of this added rubber are substantially the same as those of the rubber within and around the threads or the like.  Effective union is obtained if the yarn contains substantial amounts of impregnating rubber for example not appreciably less than 40 per cent of the weight of the yarn, and if accelerators, so chosen that the vulcanization curves for the impregnating rubber and the coating rubber are the same, are incorporated with both dispersions.  The dispersion used for coating may contain vulcanizing and other agents, e.g. accelerators and activators, in amount sufficient to vulcanize both the impregnating and the coating rubber.  The formed articles may be treated in a preliminary bath containing an ammoniacal solution of a zinc salt, and a bath containing a rubber dispersion and a substance such as spindle or other mineral oil to produce tackiness.  Vulcanizing agents such as sulphur or selenium, accelerators, activators, antioxidants, plasticizers, wetting out, reinforcing, stabilizing and other agents can be made into an aqueous dispersion in a colloid mill or homogenizer and then added to the aqueous rubber dispersion used for coating. Vulcanizing agents may be omitted and the coated fabric treated successively with sulphur dioxide and hydrogen sulphide, or with sulphur chloride solution or vapour.  According to examples, rubberized yarn made by the processes described in Specifications 344,414, 405,311, 405,312 and 405,313, [all in Group V], is woven, for example, into a driving belt.  This is immersed in a dilute solution of e.g. zinc sulphate in aqueous ammonia and then in an aqueous rubber dispersion such as latex, or a dispersion containing the substance known by the Registered Trade Mark "Revertex" together with other ingredients, proportions of which are given.  The belt is then dried at a temperature of 70 DEG  F., rising gradually to 120 DEG  F.  The preliminary zinc bath may be replaced by a rubber dispersion containing spindle oil. Specification 337,359, [Class 70], also is referred to.ALSO:Threads, yarns, or the like are impregnated with an aqueous dispersion of rubber while the said dispersion is subjected to fluid pressure and formed by weaving, braiding or like operation, into articles which are treated with a dispersion of rubber having the same stress. qtrain characteristics.  The yarn may contain substantial amounts of impregnating rubber, for example, not appreciably less than 40 per cent of the weight of the yarn, and accelerators, so chosen that the vulcanization curves for the impregnating rubber and the coating rubber are the same, may be incorporated with both dispersions.  The dispersion used for coating may contain vulcanizing and other agents, e.g. accelerators and activators, in amount sufficient to vulcanize both the impregnating and the coating rubber.  The process may be used in conjunction with those described in Specifications 344,414, [Group VIII], 405,311, 405,312, and 405,313.